For years attempts have been made to develop various types of vehicular safety systems to warn drivers of various imminent or existing unsafe driving conditions of the sort typically resulting from the drivers operation of their own vehicle. Such efforts have usually been directed to various types of safety systems that either warn a driver of obstacles directly in the path of the car or provide a warning when a vehicle equipped with the safety device is following to closely behind another automobile. Efforts have also been made to incorporate examples of the latter safety system into conventional vehicular speed control devices of an automobile (i.e. cruise control). Still another type of safety system has been proposed that warns drivers of another automobile following too closely behind a vehicle equipped with the safety system. Vehicular safety devices have also been developed in connection with collision avoidance when a vehicle is backing up such as, for example, when a commercial freight vehicle is backing up to a loading dock.
U.S. Pat. No. 5,206,153 to Suzuki, et al. and U.S. Pat. No. 5,039,271 to Maekawa, et al., provide examples of vehicular safety systems intended to warn a driver when following another automobile to closely. U.S. Pat. No. 5,937,746 to Tendlet and U.S. Pat. No. 4,864,298 to Dombrowski in turn provide examples of safety systems for warning a driver of eminent obstacle collision when a vehicle is backing up. An example of a system for providing distance information to a commercial truck backing up to a loading dock is shown in U.S. Pat. No. 4,974,251 to Bolz, et al. A safety system for warning drivers of other automobiles following to closely behind a vehicle equipped with the safety system is disclosed in U.S. Pat. No. 5,162,794 to Seth.
Regrettably the various types of vehicular safety systems discussed above almost invariably suffer from a number of impractical and expensive deficiencies. Both forward and rearwardly directed sensing system typically suffer from an unacceptably high number of false alarms. To date, none of these proposed systems have proved sufficiently practical to achieve widespread implementation. Thus, there still exists a need for a suitable vehicular collision avoidance system that can avoid false alarms, and which is susceptible to practical and economic implementation. The present invention fulfills this longfelt need.